Apparatus and a method for producing oval plastic containers

ABSTRACT

An apparatus is provided for producing plastic containers, comprising a heating device that heats plastic preforms, and including a shaping device provided downstream of this heating device in the transport direction of the plastic preforms, which shaping device shapes the plastic preforms into the plastic containers, wherein a tempering device for tempering the plastic preforms heated by the heating device is provided in the transport direction of the plastic preforms between the heating device and the shaping device, which tempering device has at least one tempering unit provided on a carrier rotatable about a predetermined rotary axis, and which tempering unit has at least two contacting devices, between which at least one section of the plastic preform can be received, which contacting devices can be moved in relation to one another along a predetermined direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Application No. 10 2015 109120.8 having a filing date of Jun. 9, 2015 the entire contents of whichare hereby incorporated by reference.

FIELD OF TECHNOLOGY

The following relates to an apparatus and a method for producing plasticcontainers. Such plastic containers and such methods have been known fora long time. Usually, these containers have a circular cross section. Insome situations, however, it may be desired to produce containers thathave a different cross section, such as an oval cross section. In thiscase it is possible to initially heat a plastic preform unevenly andsubsequently to expand it in this unevenly heated condition in thecircumferential direction using a blow moulding machine such as forexample a stretch blow machine. By means of this method, an unevenheating profile is applied to the plastic preform in the circumferentialdirection.

BACKGROUND

In another approach that has become known through the applicant, theplastic preform is, to start with, evenly heated in an oven and issubsequently tempered differently, for example “cooled”, in certainplaces in a targeted manner. The term “cooling” is here not necessarilyunderstood to mean cooling at a low temperature, but rather a targetedand partial tempering of the preforms at a temperature that is below thetemperature the preforms have after having been heated in the oven. Thismeans that the partial tempering is carried out at a temperature that issubstantially cooler or lower compared to the temperature of thepreforms after having been heated in the oven. In this method, anintermediate module is provided downstream of the heating oven, whichpartially tempers the plastic preforms by means of embossing plates.More specifically, in the method known from the applicant, the plasticpreform is inserted between two embossing plates along the longitudinaldirection thereof or vertically. This vertical movement can be achievedvia a continuous groove cam. Subsequently, the embossing plates areactuated via a drive device for each station and, if needed, the plasticpreform is rotated.

With this approach, different problems arise. To ensure that the plasticpreform can be transferred to the apparatus for tempering by a furthertransport device such as for example a reduction star wheel, the plasticpreform is held by this further transport device and a mandrel or, morespecifically, a holding mandrel of the actual tempering apparatus ismoved into the mouth of the plastic preform. In this way, verticalforces occur during the insertion process, which however are frequentlytoo high for the clamp of the input star wheel.

In order to absorb these vertically occurring forces, stationary supportmodules are required which can lead to a subsequent twisting of theplastic preform, so that the orientation process of the plastic preformmay become incorrect, because a rotary position of the plastic preformis usually detected prior to its input into the station. However, theorientation process itself will only be carried out within the stationvia a stepper motor. This means, should the preform be accidentallytwisted again on its way between the camera inspection and theorientation, the orientation process would be incorrect and the correctrotary position would not be reached. The orientation of the plasticpreform or the rotary position thereof is of high significance for theapplication of the temperature profile onto the required places in atargeted manner. Apart from that, for moving the plastic preform betweenthe embossing plates, the high vertical lift requires a large, complexand expensive lifting cam in the prior art, which causes high loads onthe traversing slide. Apart from that, process time is lost as a resultof this traversing movement.

A further problem arises partially during the opening and closingmovement of the embossing plates (referred to below as contactingdevice). To this end, pneumatic cylinders are used in the applicant'sinternal art. Pneumatic cylinders do not ensure a constant andconsistent switching time, so that as a rule, a certain scatteringoccurs between the different treatment stations. The different embossingtimes or contacting times, in which the embossing plates touch the outerwalls of the plastic preforms, reduce the quality of the mouldedbottles.

The present invention is therefore based on the aspect of designing themanufacturing process for such non-circular containers in a simpler way.Apart from that, also the possibility is to be provided to reducedeviations between individual treatment stations.

SUMMARY

An aspect relates to producing plastic preforms comprising a heatingdevice that heats plastic preforms, as well as a shaping device thatshapes or expands the plastic preforms into the plastic containers andis installed downstream of this heating device in a transport directionof the plastic preforms, wherein in the transport direction of theplastic preforms, a tempering device for (in particular partial andespecially partial in the circumferential direction of the plasticpreform) tempering of the plastic preforms heated by the heating deviceis provided between the heating device and the shaping device, andwherein this tempering device has at least one tempering unit providedon a carrier that can be rotated about a predetermined rotary axis, andthis tempering unit has at least two contacting devices, between whichat least one section of the plastic preforms can be received, and thesecontacting devices can be moved relative to each other along apredetermined (movement) direction.

According to embodiments of the invention, this predetermined directionof the movement of the contacting devices relative to each other extendsat an angle that is different from 0° relative to the radial directionof the carrier. Apart from a tangential movement, also a pivotingmovement for opening and closing the contact elements is conceivable.

Heretofore, the contacting devices are orientated such that an openingand closing movement is carried out in a radial direction or in adirection that is perpendicular to the axis of the carrier wheel. Sofar, this has been designed in a way so as to save space between theindividual treatment stations. However, such an opening and closingmovement allows the preforms to be introduced into the stationexclusively from the top or the bottom, which should be avoided becauseof the disadvantages mentioned.

Preferably, the contacting devices touch the plastic preform and temperthe latter in the circumferential direction thereof in sections orpartially. In this way, a certain temperature profile can be generatedin a circumferential direction of the plastic preforms, as a result ofwhich the material of the preform will behave differently in theseplaces than in the non-tempered places during the later shaping process.Advantageously, the tempering device includes a plurality of temperingunits which are each provided on said carrier. Tempering the plasticpreforms is understood here in particular to mean to apply a temperaturethereto that differs from the temperature of the plastic preforms afterhaving been heated in the oven. In particular, tempering is a cooling ofthese sections of the plastic preform. In particular, certain wallsections of the circumferential wall of the plastic preform aretempered. Preferably, the tempering device includes a plurality oftempering units provided on the carrier.

In a further advantageous embodiment, the heating device is an infraredoven that heats the plastic preforms using infrared radiation. However,it would also be possible to use a microwave heating unit. Preferably,this heating device has a transport device for transporting the plasticpreforms. Preferably, the heating device includes heating elements thatheat the plastic preforms. Particularly preferably, these heatingelements are provided to be stationary relative to the transportmovement of the plastic preforms.

The above-mentioned relative movement of the one contacting devicerelative to the other contacting device is understood to mean that atleast one contacting device is moved, for example for contacting theplastic preforms, towards the other contacting device. Preferably,however, both contacting devices are moved relative to each other. Inparticular, this is a uniform movement of both contacting devices.Preferably, the contacting devices are moved along a rectilinear path.This is in particular an opening and closing movement. The contactingdevices may however also be pivoted, or the movement could extend alonga circular-segmented path.

Preferably, the predetermined direction deviates from said radialdirection by at least 10°, preferably by at least 20° and particularlypreferably by at least 30°. Preferably, the predetermined directionextends relative to the radial direction at an angle of at least 50°,preferably of at least 60° and preferably of at least 70°.Advantageously, said direction of movement extends tangentially to saidcarrier on which the heating units are disposed.

Advantageously, this is also a movement that is tangential to atransport movement of the plastic preforms. Advantageously, the plasticpreforms are moved along a circular transport path during theapplication of the heating profile onto the circumferential wall.

In a further advantageous embodiment, the contacting devices contact anouter wall of the plastic preforms. In doing so, these contactingdevices preferably cool the outer wall of the plastic preforms. Coolingis here understood to mean cooling in relation to the temperature theplastic preforms have when they exit the oven. This may for example be120°, and correspondingly the temperature of the contacting device mayfor example be 50°.

The above-mentioned aspects are therefore correspondingly achieved alsoby means of a tempering device for tempering plastic preforms, whichtempering device has at least one tempering unit that is provided on acarrier that can be rotated about a predetermined rotary axis, and thistempering unit has at least two contacting devices that are suitable andintended for contacting an outer wall of the plastic preforms, andbetween which at least one section of the plastic preform can bereceived. These contacting devices are, as mentioned above, movablerelative to each other along a predetermined direction.

According to embodiments of the invention, the predetermined directionextends at an angle that is different from 0° relative to a radialdirection of the carrier.

In a further advantageous embodiment, the above-mentioned apparatusincludes a feeding device that feeds the plastic preforms to thetempering unit or the tempering device, and this feeding device suppliesthe plastic preforms to the tempering unit or the tempering device in afeeding direction that is substantially perpendicular to a longitudinaldirection of the plastic preforms.

The following is further directed to a method for producing plasticcontainers, wherein plastic preforms are heated by means of a heatingdevice and the plastic preforms thus heated are shaped into the plasticcontainers by means of a shaping device that is provided downstream ofthe heating device in a transport direction of the plastic preforms, andthe plastic preforms are tempered in sections by means of a temperingdevice after having been heated by the heating device and prior to theshaping by the shaping device. According to embodiments of theinvention, the plastic preforms are fed to the tempering device in afeeding direction that extends in a plane that is substantiallyperpendicular to a longitudinal direction of the plastic preforms.Preferably, the plastic preforms are transported during the feedingthereof to the tempering device and also during the transport therewithat a constant vertical height.

With this approach, the plastic preform or the plastic container istherefore moved, during the transfer from this feeding device to theheating unit and preferably during the entire passage, substantiallywithout any change to its vertical position. The plastic preform is atleast not moved in its vertical direction during the transfer from saidfeeding device to the tempering unit. However, the plastic preform ispreferably moved during its entire treatment (in particular during theheating and the subsequent tempering) and/or its entire passage, i.e.through the heating device, by the feeding device (which may for examplebe an intermediate star wheel) and the subsequent shaping deviceswithout any change to its vertical position.

Preferably, the tempering device transports the plastic preforms along acircular transport path, and for tempering the plastic preforms, atleast two contacting devices are advanced, wherein the advance movementis carried out in a direction that extends in a direction that isdifferent from 0° with regard to a radial direction of this transportpath. In particular, this advancement takes place along a direction thatincludes an angle of at least 20°, preferably of at least 30°,preferably of at least 50° and particularly preferably of at least 70°with the radial direction of the transport path.

Further, as mentioned above, the direction of the opening movement ofthe contacting devices (or embossing plates) is substantially tangentialto the treatment wheel, i.e. to the tempering device. The plasticpreform is preferably introduced between the contacting devicessubstantially perpendicularly to a direction of movement or traverse ofthe latter. In other words, said feeding device feeds the plasticpreforms towards the tempering unit substantially perpendicularly to thepredetermined direction in which the contacting devices move. In thisway, a particularly accurate transfer may be achieved and, as mentioned,any vertical movement of the plastic preforms can be dispensed with.Preferably, a horizontal plane is formed by the movement direction ofthe contacting devices on the one hand and the feeding direction inwhich the plastic preforms are fed to the tempering unit.

In detail, the following method steps are preferably carried out:

-   -   removing the plastic preform from the heating device    -   transferring the plastic preform heated by the heating device in        a first holding device of a tempering unit of the tempering        device, which first holding device is designed as a gripping        device    -   closing the gripping device of the tempering unit    -   vertically introducing a second holding device into the mouth of        the plastic preform    -   advancing the contacting device towards the plastic preform for        tempering the latter    -   moving the contacting device away from the plastic preform    -   removing the tempered plastic preform via a further transport        device    -   removing the second holding device from the mouth of the        tempered plastic preform.

Within the context of advancing the contacting devices, for example thecontacting devices or embossing plates may be closed around the plasticpreform. For the purpose of moving the contacting devices away, theembossing plates may correspondingly be opened. The second holdingdevice, which is in particular formed as an internal gripper for theplastic preforms, may also be withdrawn from the mouth thereof at anearlier point in time. Further, a rotation of the plastic preform inrelation to its longitudinal axis may optionally be carried out. Withinthe context of this rotation, the plastic preform may be rotated inrelation to its thread position or in relation to an alignment markingof the thread.

In a further embodiment according to the invention, the tempering devicefor tempering plastic preforms again includes a tempering unit providedon a carrier that can be rotated about a predetermined rotary axis, andthis tempering unit has at least two contacting devices that aresuitable and intended for contacting an outer wall of the plasticpreforms, and between which at least a section of the plastic preformcan be received. Further, the apparatus has here a drive device formoving the contacting devices.

According to embodiments of the invention, the drive device has anactuator device that drives and/or moves at least one contacting device.Whilst known guide cams are used that drive and/or move the contactingdevices, it is now proposed for the contacting device to have associatedtherewith an actuator device that generates these movements or thatdrives the contacting devices.

Advantageously, the tempering device includes a plurality of temperingunits and each of these tempering units has an actuator device. In thisway, an individual control of the individual actuator devices and thusan individual movement of the individual contacting devices becomepossible.

Preferably, a movement of the first contacting device is coupled with amovement of the second contacting device by means of at least onecoupling device. It is therefore proposed in this embodiment that themovements of the contacting devices are not controlled separately orindependently of each other, but that they are coupled together. In thisway, a particularly uniform movement can be achieved.

In a further advantageous embodiment, the feeding device includes arotatable carrier and a plurality of holding devices disposed on thiscarrier for holding the plastic preforms. In this respect, the feedingdevice may have for example a plurality of gripping clamps that hold theplastic preforms and are used for transferring the plastic preforms tothe tempering units. These holding devices may for example be grippingclamps that carry the plastic preforms in a predetermined region, forexample below a so-called carrier ring. Preferably, these holdingdevices are mounted so as to be movable in their entirety in relation tothe carrier of the feeding devices, for example on a pivotable arm, andare, if necessary, also movable in a radial direction of this carrier.Advantageously, this feeding device is a so-called reduction star wheelthat is used and intended for changing a separation of the individualplastic preforms on the transport path from the heating device to thetempering device. Usually, the plastic preforms are transported in theheating device at a distance that is much smaller than in the temperingdevice. The reduction star wheel is used for changing this distance.

In a further advantageous embodiment, the tempering device has at leastone first holding device for holding the plastic preforms and inparticular a plurality of holding devices for holding the plasticpreforms. In particular, each tempering unit has here associatedtherewith such a holding device for holding the plastic preforms. Inparticular, this is a gripping clamp that grips the plastic preform bythe external surface thereof and in particular on or below the threadthereof, and holds it in this way. The apparatus known do not have sucha gripping device. In this context, the plastic preform has so farusually been transferred by the gripping device to the feeding device,such as the reduction star wheel, on a holding mandrel of the temperingdevice.

It is proposed within the scope of the present apparatus that theplastic preform is taken out of the heating device via an intermediatestar wheel, such as for example a reduction star wheel, and istransferred via the latter to said gripping device of the temperingunit, for example on a clamp located on the embossing station. In thisway, the plastic preform may already be located in a target position andonly afterwards is it possible that for example a mandrel of thetempering unit engages in a mouth of the plastic preform. Preferably,each tempering unit has associated therewith both a first holdingdevice, in particular in the form of said gripping clamp, and a secondholding device, in particular in the form of a holding mandrel.Advantageously, these two holding devices hold the plastic preformtogether, at least temporally.

Preferably, as mentioned, a movement of the first contacting device iscoupled with a movement of the second contacting device. In thiscontext, the apparatus in particular includes a mechanical couplingdevice. Also the use of an electronic coupling would be conceivable, forexample a control-side coupling that controls the drives of twocontacting devices. Preferably however, said mechanical coupling deviceis provided. In this context, for example as described in more detailbelow, this coupling can be realised via a linkage. In this embodimentit is possible to provide only one actuator or one drive device, andsaid coupling device transfers the movement of this actuator to bothcontacting devices. This coupling makes it possible for both contactingdevices to move substantially at the same time and in particular also ina rectilinear manner, in particular a movement is conceivable thatensures that a geometrical centre between the two contacting devicesremains constant during the advance movement of the contacting devicestowards each other. Advantageously, also a longitudinal axis of theplastic preform is located in this geometrical plane or in thisgeometrical centre. In this way, the two contacting devices may beuniformly advanced towards the plastic preforms (or be removedtherefrom).

In a further advantageous embodiment, the tempering unit has a rotarydevice for rotating the plastic preforms in respect of the longitudinaldirection thereof. This rotary device may here include a further holdingelement that holds the plastic preform. This further holding element orthis further holding device may in particular be a mandrel that engagesin a mouth of the plastic preform. In the course of this process, theplastic preform can initially be held by the gripping clamp,subsequently said mandrel can engage in the plastic preform and caneffect in this way (in particular after the gripping clamp has beenopened) also a rotation about the longitudinal direction thereof.

In a further advantageous embodiment, the diameters of this internalgripping for the plastic preform of the clamp for holding the plasticpreforms and also the diameters of the contacting devices are locatedcoaxially on top of each other. In this way it can be achieved that inthe case of individual transfers, and also during the tempering of theplastic preform, no forces acting in the direction perpendicular to thelongitudinal direction of the plastic preform occur.

Preferably, the apparatus includes a second holding device for holdingthe plastic preforms, which can be inserted into the mouth of a plasticpreform.

In a further advantageous embodiment, the apparatus includes a rotaryposition detection device that detects a rotary position of the plasticpreforms in relation to the longitudinal directions thereof (inparticular in a contactless manner). This may for example be an opticaldetection device that detects a certain marking of the plastic preformand detects, by means of the position of this marking, the rotaryposition of the plastic preform. This marking is here preferably locatedin a certain place on the external circumference that is characteristicof a rotary position of a thread of the plastic preform. As a responseto the rotary position thus detected, the rotary position of the plasticpreform may be adjusted.

This means, whilst in the related art the plastic preforms aretransferred directly from the feeding device to the holding mandrel, inthe context of embodiments of the invention, it is also advantageouslyproposed that the plastic preforms are initially transferred to aholding device or a gripping clamp, which is in each case associatedwith the individual tempering units.

In a further advantageous embodiment, the apparatus has an actuatordevice that effects both the movement of the first contacting device andthe movement of the second contacting device. This actuator device ordrive device may for example be an electric motor, however, it wouldalso be conceivable to use pneumatic, hydraulic or magnetic drives. Alsoa guide cam would be conceivable as a drive device. In other words, theactuator device is selected from a group of actuator devices thatincludes electrically operated actuator devices, hydraulically operatedactuator devices, pneumatically operated actuator devices and/ormagnetically operated actuator devices.

In a further advantageous embodiment, the movements of the twocontacting devices are coupled via a mechanical linkage. This linkagemay here, as will be explained in more detail below, be articulated to arotatable body. Thus, it would for example be possible for the actuatordevice to carry out a translatory traversing movement, which istranslated via the linkage into a rotary movement and/or into a furthertranslatory movement of the other contacting device. Apart from that, itwould also be possible for the translatory traversing movement of thecontacting devices to be derived from a rotary movement. Apart from thatit would also be conceivable that the translatory traversing movement ofthe two contacting devices is derived directly from a rotation of anactuator device, for example of an electric motor.

As has already been mentioned above, this kinematic is preferablydesigned in such a way that the contacting devices or the receptaclesfor the contacting devices move tangentially to a main rotary directionof the receptacle wheel or of the carrier, and particularly preferably,the movement of the two contacting devices is realised in the oppositedirection towards a centre. In this way, a uniform advance movement ofthe contacting devices towards the plastic preform is conceivable.

In a further advantageous embodiment, the apparatus has a stop or a stopdevice, which defines a limit position of the contacting elements. Thusfor example, a stop may be located on the receptacle devices for thecontacting device, which defines a central position of the contactingdevices and particularly preferably also limits the force acting on theplastic preform.

In a further advantageous embodiment it would be conceivable that thecontacting devices can be removed from the carrier associated therewitheven in a longitudinal direction of the plastic preform.

In a further advantageous embodiment, the actuator device is located ona slide. Thus for example, also a linear motor could be used as anactuator device.

In a further advantageous embodiment, the coupling device has at leastone rod-shaped body, via which a contacting device is articulated. Thusfor example, the contacting device may be articulated to a rotatableelement via the rod-shaped body.

In a further advantageous embodiment, the coupling device has arotatable carrier, to which the contacting devices are articulated viathe linkage. As will be explained in more detail below, such anarticulation may also allow a uniform advance movement to be achieved.

In a further advantageous embodiment, the apparatus or the temperingdevice has a first holding device for holding the plastic preforms.Advantageously, as mentioned above, the tempering device also includes asecond holding device for holding the plastic preforms. Advantageouslyhere, one of these holding devices may be formed as a gripping clamp,the other one as a holding mandrel.

Preferably, an electric drive device may here be provided for thegripping clamp, which effects an opening and closing movement of thisgripping device. Advantageously, the first holding device is thereforeswitchable, i.e. this is in particular an active holding device or anactive gripping clamp that can be switched and in this way closed andopened.

In a further advantageous embodiment, the coupling device couples themovement of the first contacting device to the movement of the secondcontacting device in such a way that the first contacting device and thesecond contacting device move (in particular uniformly) in oppositedirections. This movement may here be an advance movement towards theplastic preform, but it may also be a movement away from the plasticpreform. Preferably, these are here rectilinear movements.

As mentioned above, the tempering unit preferably includes a rotarydevice for rotating the plastic preforms in respect of the longitudinaldirections thereof. This rotary device may in particular, but notexclusively, be a stepper motor.

In a further advantageous embodiment, the coupling device is providedwithin a transport path, along which the plastic preforms aretransported by means of the tempering unit. Advantageously, thistransport path is, as mentioned above, a circular transport path.Preferably, also the actuator devices are provided within this transportpath. Thus for example, the actuator devices may, compared with a pitchcircle of the treatment wheel, i.e. the circle on which the plasticpreforms are transported during the tempering thereof, be placed on acircle having a smaller diameter.

In a further advantageous embodiment, at least one contacting device andpreferably both contacting devices may have a flowable and in particulara liquid tempering medium flowing through them. Thus, channels may beprovided on the inside of these contacting devices, through which atempering medium can flow. By means of this tempering medium, thecontacting devices can be maintained at a certain temperature level, forexample at 50° C.

In a further preferred embodiment, said holding device for the plasticpreforms may be located above the contacting devices. Here, this holdingdevice may be actively switchable.

In a further advantageous embodiment, the contacting devices are eachprovided on carriers, and particularly preferably, they are held onthese carriers by a force- and/or form-locking connection.

In a further advantageous embodiment, the movements of the firstcontacting devices and of the second contacting device are coupled insuch a way that the contacting devices move in a direction that includesan angle that is different from 0° with a radial direction of the maincarrier. In particular, this is a direction that is substantiallytangential to the main rotary direction of the plastic preforms, asmentioned above.

In a further advantageous embodiment, an opening lift between thecontacting devices is smaller than 70 mm, preferably smaller than 60 mmand particularly preferably smaller than 55 mm. This opening lift issufficient for introducing a plastic preform between the contactingdevices perpendicularly to the longitudinal direction thereof. Asmentioned above, the plastic preform is preferably introduced betweenthe contacting devices perpendicularly to the longitudinal directionthereof.

The following is further directed to a tempering device for temperingplastic preforms, which tempering device has at least one tempering unitprovided on a carrier that is rotatable about a predetermined rotaryaxis, and this tempering unit has at least two contacting devices thatare suitable and intended for contacting an outer wall of the plasticpreform, and between which at least a section of the plastic preformscan be received. Further, this contacting device includes a drive devicefor moving the contacting devices in a predetermined direction ofmovement.

According to embodiments of the invention, the apparatus includes adetection device in order to detect, at least temporally, a position ofat least one contacting device in the predetermined direction ofmovement.

As mentioned above, an opening and closing movement of the contactingdevice may be carried out via a control using pneumatic cylinders. Inthe case of pneumatic cylinders, as mentioned above, no constant andconsistent switching time can be ensured, and for this reason ascattering of the treatment times between the individual treatmentstations has to be expected. In order to counteract such scattering itis proposed to measure the opening and closing times and to detect theposition of the embossing plates. To this end, it would be possible todetect a position of the contacting devices via a detection device. Inthis way, the movement can be controlled.

Advantageously, a plurality of tempering units is provided on thecarrier and each tempering unit has a detection device in order todetect, at least temporally, a position of at least one contactingdevice in the direction of movement. In other words, the relativeposition of the contacting device in relation to the plastic preform tobe tempered is preferably detected.

In a further advantageous embodiment, the apparatus includes a controldevice in order to control the drive device as a function of thedetected position of the at least one .contacting device. In particular,a control of the contacting device (in particular the movement thereof)or a control of this drive device is carried out.

In a further advantageous embodiment, the drive device is a pneumaticdrive device. However, also hydraulic, magnetic or electric drivedevices would be conceivable.

In a further advantageous embodiment, the tempering device includes atime measurement device. Preferably, the time measurement device issuitable and intended for detecting a temporal distance between a firstsignal that is characteristic of the control of the drive device and asecond signal that is characteristic of a position of the contactingdevice.

In this embodiment it is possible for the position of the contactingdevice to be polled via a detection device such as for example aproximity switch. In each individual heating unit, the time between theelectrical switch signal and an actuation of the detection device, inparticular a proximity switch, can be measured, particularly preferablyindependently of each other during closing and during opening. A risingedge of the valve control of the pneumatic drive device may be presenthere until the contact devices are closed, and a falling edge of thevalve control may be present until the contacting devices are opened.During the next passage of the contacting device or of the temperingunit, the measured times may be calculated in as a reference value or asa lead value. This means that the control signal will be output earlierthan the desired target time by the measured time. In this way, theindividual station values can be adapted to each other, so that thecontacting of the plastic preforms will always be carried out in exactlythe same way.

Apart from that, again also a measurement can be carried out which willthen in turn be used for the next cycle. In this way, a slow driftingaway, which may occur for example during a running-in period, may becompensated.

In addition it would be possible that in a special running-in process,which is carried out for example after a prolonged standstill period ofthe system, the contacting device can be operated in an empty conditionfor one cycle even before the input of the first plastic preform, andthe delay times may be measured. In this way, the circumstance may betaken into account .that the last measurement is a long time back andthe times might have changed too much during a standby operation.

Preferably here too, a movement of the first contacting device iscoupled with a movement of the second contacting device by means of acoupling device. As mentioned, the coupling device may here again be amechanical coupling device.

The following is further directed to a method for treating containersand in particular for treating plastic containers. Here, a plurality ofsubstantially similar treatment stations is provided, which treat thecontainers substantially in the same way using at least one treatmentelement. Further, in each case the at least one treatment element ismoved relative to the container to be treated by means of pneumaticdrives that are each associated with the respective treatment stations.According to embodiments of the invention, at least one value isdetected by means of a detection device, which is characteristic of ageometric position of the treatment element relative to the container,and/or at least one first time value is determined that ischaracteristic of reaching a geometric position of the treatment elementin relation to the container, and on the basis of this measured value,the pneumatic drive is controlled.

Therefore, it is also proposed on the side of the method that thepneumatic drive is open-loop controlled and in particular closed-loopcontrolled, namely in particular on the basis of values that weredetermined for exactly this treatment element. Preferably, the drive isclosed-loop controlled, and particularly preferably on the basis of afirst measured value, a change to the drive or to a drive parameter iscarried out, and preferably said values are again determined in afurther cycle.

The concept described here can be used in particular for adapting theparameters of a plurality of treatment elements to each other, so thatin all treatment stations, container treatment steps of substantiallythe same type are carried out.

The following is here in particular described again in the light of thecontacting devices already described above, however it is pointed outthat the concept described here can also be used on other machines, inwhich the containers are treated using treatment elements, for exampleheating devices, shaping devices or filling devices. The containers maybe both plastic preforms and plastic containers such as plastic bottles.

Preferably, therefore, the time values of a plurality of treatmentstations are measured and the pneumatic drives of the individualtreatment stations are controlled in such a way that the treatment timesof the respective containers with the respective treatment elements forthe individual treatment stations are matched to each other.

In a further preferred method, the measured values for the positionsand/or the time values are stored.

In a further preferred method, a switching point of at least one valveof the pneumatic drive device is controlled. Particularly preferably,the switching points of the individual valves of the pneumatic drivedevices of the individual treatment stations are controlled and adaptedto each other in particular in such a way that a consistent treatment ofthe respective containers using the individual treatment units iscarried out.

In a further preferred embodiment, the treatment element is a contactingdevice that contacts a plastic preform for the tempering thereof. In themethod described here, the contacting times of the individual plasticpreforms with the contacting devices can be matched to each other, andin this way a consistent tempering of the plastic preforms can becarried out.

BRIEF DESCRIPTION

Some of the embodiments will be described in detail, with reference tothe following figures, wherein like designations denote like members,wherein:

FIG. 1 shows a detailed view of a treatment device;

FIG. 2 shows a view for feeding plastic preforms to a treatment device;

FIG. 3 shows a lateral view of the treatment device shown in FIG. 1;

FIG. 4 shows a further view of the treatment device;

FIG. 5 shows a view of an entire system for treating plastic containers;

FIG. 6 shows a further view of a system for treating containers;

FIG. 7 shows a view of a treatment device;

FIG. 8 shows a detailed view of the treatment device shown in FIG. 7;

FIG. 9 shows a front view of the treatment device shown in FIG. 7;

FIG. 10 shows a further detailed view of a treatment device;

FIG. 11 shows a further detailed view of a treatment device; and

FIG. 12 shows a further detailed view of a treatment device.

DETAILED DESCRIPTION

FIG. 1 shows an apparatus for tempering containers and in particularplastic preforms according to the related art. This apparatus includeshere a rotatable carrier 412, on which a plurality of treatment units440 is provided. These treatment units each have a first contactingdevice 444 and a second contacting device 446, which are suitable andintended for contacting a plastic preform, of which here only a thread10 a can be seen, on the outer wall thereof. These contacting devices444, 446 may here have walls, which can be placed against certainregions of the plastic preforms, in order to temper the latter and inparticular to cool them in relation to the temperature the plasticpreforms have when they exit an oven. In this context, the plasticpreform is pushed between the two contacting devices 444 and 446 alongthe longitudinal direction thereof, i.e. the plastic preforms arevertically lifted. Further, the contacting devices 444, 446 are pushedapart in the radial direction of the carrier 412, which is illustratedby the arrow O. After this opening, the plastic preform is inserted andthe contacting devices are advanced towards the plastic preform.

FIG. 2 illustrates the entire process. It can be seen here that theplastic preforms are fed by a gripping clamp 420 of a feeding device 414directly to the individual treatment units. More specifically, theheated plastic preform is transferred, via the feeding device 414 or thereduction star wheel 414, directly to the internal gripper of theindividual treatment units and is subsequently displaced downwards inthe longitudinal direction thereof.

FIG. 3 shows a further detailed view of a corresponding apparatusaccording to the related art. What can be seen here again is the plasticpreform 10 or the mouth 10 a thereof, which protrudes from the temperingunit 440. It can be seen that the contacting devices are here opened andclosed in the radial direction thereof.

FIG. 4 shows a correspondingly enlarged view. In particular, it can beseen in this view that the treatment units do not have their owngripping element for holding the plastic preforms, but that the holdingof the plastic preforms is carried out merely via the internal gripperthat engages in the mouth 10 a of the plastic preforms.

FIG. 5 shows an illustration of a system 50 for treating containers.This has here a heating device 2, such as an oven, through which theplastic preforms are passed. Subsequently, the plastic preforms aretransferred to the tempering device 4 by means of a transfer star wheel,and from there in turn, in the tempered condition, to a shaping device6, for example a blow moulding machine. In this blow moulding machine,containers are here shaped or stretch-blown so as to have a crosssection that deviates from a circular cross section.

FIG. 6 shows a further, more accurate view of a system 50 for producingplastic containers. In this system 50, the plastic preforms are alsoinitially made by means of a production device 80 and are subsequentlyfed to the heating device 2 via a feeding device 82 and a so-calledsynchronisation star 84. The synchronisation star separates theindividual plastic preforms or forms a predetermined pitch between them.This heating device 2 has a plurality of heating elements 22, which arehere mounted to be stationary and along which the plastic preforms arepassed. In the course of this, all of the plastic preforms areconsistently heated.

Reference numeral 12 identifies a feeding device that transfers theplastic preforms to the tempering device 4. This feeding device 12 is,as mentioned above, a so-called reduction star wheel. The temperingdevice has a carrier that can be rotated about a rotary axis D, on whicha plurality of tempering units is provided. Reference numeral 49identifies a housing surrounding the tempering device 4. The shapingdevice 6 also has a rotatable carrier 62, on which a plurality ofshaping stations 64 is provided. Reference numeral 66 identifies acontrol device for controlling the shaping device 6, and referencenumeral 68 identifies a discharge device for discharging the finishedcontainers. Reference numeral 70 identifies a control device forcontrolling the heating device 4. Reference numeral 45 identifies arotary position detection device that detects a rotary position of theplastic preforms in respect of the longitudinal direction thereof.

FIG. 7 shows a view of an apparatus according to embodiments of theinvention for tempering plastic preforms. This apparatus, too, has heretwo contacting devices 44 and 46, however, an advance movement iscarried out along the arrow B, which is here substantially perpendicularto a radial direction R of the carrier 42, on which the heating unit 40is provided. Reference numeral 48 identifies a holding device, such ashere a gripping clamp, which is used for gripping the plastic preform.During the tempering process therefore, the plastic preform is also heldby this gripping clamp 48. This gripping clamp 48 is provided to bestationary relative to the carrier 42 or to be stationary apart from itsactual gripping movement.

The plastic preform is input into this gripping device 48 and is heldthereby, until a holding mandrel 16 (i.e. the second holding device) hasbeen introduced into the mouth of this plastic preform. The plasticpreform is rotated, if necessary, in respect of the longitudinaldirection thereof, in order to orientate the thread, and subsequentlythe contacting devices 44 and 46 are uniformly advanced to the plasticpreform, in order to temper the latter on the outer circumference or theouter wall thereof. For the purpose of introducing the second holdingdevice into the mouth of the plastic preform, a guide roller 72 isprovided, which causes the second holding device 16 to be advancedtowards the plastic preform.

Reference numeral 74 identifies a carrier, on which the second holdingdevice 16 is provided. Reference numeral 14 identifies a rotary device,such as a stepper motor, which is used for rotating the plastic preform10 in respect of the longitudinal axis thereof. By means of this rotarydevice 14, an orientation of the individual threads of the plasticpreforms can be achieved.

In the method, the plastic preform is initially introduced into thefirst holding device 48 in a horizontal direction, and subsequently,also the second holding device 16 is introduced into the mouth of theplastic preform. Also a rotary position of the thread of the plasticpreform may be detected after the transfer thereof into the firstholding device 48. In this position, the plastic preform can then berotated in respect of the longitudinal direction thereof. After thetempering, the plastic preform is again removed from the holding device48 via an intermediate star wheel (not shown). Thus, the holding device48 is an active element that can therefore be actively opened andclosed. An opening can be carried out for example in order to rotate theplastic preform in respect of the longitudinal direction thereof.

Preferably, the plastic preform is input into the tempering device insuch a way that a (circumferential) angle of more than 250°, preferablymore than 270° and particularly preferably of more than 290° is achievedbetween the discharge point and the input point. In other words, theplastic preform is transported about the mentioned circumferential anglebetween the input point and the discharge point. Along this processangle, a tempering of the plastic preform is thus carried out. As aresult of this comparatively large process angle, a substantiallyconsistent tempering of all the plastic preforms can be facilitated.

In detail, the plastic preform is initially removed from the oven shownin FIGS. 5 and 6, and this is preferably carried out by means of areduction star wheel. Subsequently, the heated plastic preform is passedfrom this reduction star wheel into the first holding device 48 which,as mentioned above, is provided on the carrier 42 and above the twocontacting devices 44 and 46. Subsequently, the holding device 48 isclosed in order to hold the plastic preform 10. In a further methodstep, the second holding device 16 is moved into the mouth of theplastic preform, and this movement is carried out in a verticaldirection (i.e. in the longitudinal direction of the plastic preform).Subsequently, the holding device 48 is opened, so that the plasticpreform is held only by the second holding device 16. If required, theplastic preform is rotated in correspondence with its orientationmarking. In this way, accurately predefined regions of thecircumferential wall of the plastic preform may be tempered.

In a further method step, the two contacting devices 44 and 46 areclosed and temper regions of the outer wall of the plastic preform.

In a further method step, the contacting devices 44, 46 are opened againand the plastic preform thus provided with a temperature profile isremoved by a removal device, which is in particular again a reductionstar wheel, of the tempering device. Subsequently, the plastic preformis transferred to the shaping device 6 shown above. Prior to the removalof the plastic preform, the holding device 16 can here be withdrawnagain from the mouth of the plastic preform. Correspondingly, the clamp48 can here also be closed again, so that again a purely horizontaltransfer of the plastic preform to the subsequent transport devices ispossible.

Reference sign B relates to the direction of movement of the twocontacting devices 44, 46. It can be seen that this direction ofmovement B is here perpendicular to the radial direction R of thecarrier 42. In other words, the movement direction B extends heretangentially to the transport path of the plastic preforms 10. However,it would also be possible to position the two contacting devices 44, 46somewhat obliquely, so that the plastic preform can be introducedbetween the contacting devices in its transport direction “from behind”.

FIG. 8 shows a detailed view of the apparatus shown in FIG. 7. It can beseen that the gripping device 48 has two clamp parts 48 a and 48 b.Reference numeral 32 schematically identifies a drive that is used foropening and closing the gripping device 48. This clamp 48 is herelocated in its entirety above the contacting devices 44 and 46. Morespecifically, a carrier of this gripping clamp 48 is provided to bestationary relative to a carrier of the two contacting devices 44 and46.

FIG. 9 shows a front view of the apparatus according to embodiments ofthe invention. Here, too, the two contacting devices 44 and 46 as wellas the gripping clamp 48 can be seen. Apart from that, also a couplingdevice is provided, which is in its entirety identified with 104 andwhich couples the movement of the first contacting device 44 with themovement of the second contacting device 46. This coupling device 104has here a rotatable carrier 112, to which the two hinge joints 114 and116 are articulated. These two hinge joints 114 and 116 are in turnconnected to the contacting devices 44 and 46 via a linkage (not shownhere). It would be possible here for the rotatable carrier 112 to bedriven by an electric motor, so that the contacting devices 44 and 46are uniformly moved apart and together via the linkage. However, itwould also be possible to drive one of the two contacting devices 44, 46by means of a linear motor, and the coupling device 104 would transmitthis movement also to the other contacting device.

FIG. 10 shows a further view of a heating unit according to embodimentsof the invention. Here, too, the second holding device 16 can be seen,which in this case is a mandrel that can be introduced into the mouth ofa plastic preform (not shown). This holding device can here be moved inthe longitudinal direction L of the plastic preform, in order to allow,as mentioned, the introduction thereof into the plastic preform or themouth thereof.

Reference numeral 122 identifies a guide roller that rolls off on aguide cam (not shown), in order to achieve in this way the introductionof the holding device 16 into the plastic preform.

FIG. 11 shows a further partial view of the coupling device 104. Here,also the two rod-shaped bodies 116 and 118 are shown, via which the twocontacting devices 44 (not shown) and 46 are articulated. Referencenumerals 132 each identify a carrier, on which a slide 134 isdisplaceably supported. On this slide, in turn, the contacting device 46is provided. This slide may also have a (linear motor) drive for movingthe contacting device 46.

Reference numerals 152 and 153 relate to connections, by means of whicha flowable medium can be fed to the contacting device 46, in order totemper the contacting device 46. Correspondingly, the contacting device46 has channels on the inside thereof for conducting this liquid medium.

FIG. 12 again shows a front view of a heating unit according toembodiments of the invention. Here, again, the two contacting devices 44and 46 can be seen, as well as a connection 154 for feeding anddischarging the flowable tempering medium.

The applicant reserves the right to claim all of the features disclosedin the application documents as being essential to embodiments of theinvention, in as far as they are novel over the related art eitherindividually or in combination. It is further pointed out that theindividual figures also describe features which, by themselves, may beadvantageous. A person skilled in the art will immediately realise thata certain feature described in a figure may be advantageous, even if nofurther features from this figure are adopted. A person skilled in theart will further realise that advantages may also result from acombination of a plurality of features shown in individual or indifferent figures.

LIST OF REFERENCE NUMERALS

-   1 Apparatus-   2 Heating device-   4 Tempering device/Heating device-   6 Shaping device-   10 Plastic preform-   10 a Thread/Mouth-   12 Feeding device-   14 Rotating device-   16 Second holding device-   22 Heating elements-   32 Drive-   42 Carrier-   44, 46 Contacting Devices-   45 Rotary position detection device-   48 Holding device/Gripping clamp-   48 a, b Clamp parts-   49 Housing-   50 System-   62 Carrier-   64 Shaping station-   66 Control device-   68 Discharge device-   70 Control device-   72 Guide roller-   74 Carrier-   80 Production device-   82 Feeding device-   84 Synchronisation star-   104 Coupling device-   112 Rotatable carrier-   114, 116 Hinge joints-   117, 118 Rod-shaped body-   122 Guide roller-   132 Carrier-   134 Slide-   152, 154 Connections-   412 Rotatable carrier-   414 Feeding device-   420 Gripping clamp-   440 Tempering unit-   444, 446 Contacting devices-   O Opening movement-   B Feeding movement-   R Radial direction-   L Longitudinal direction

1. A temperature varying device for varying the temperature of plasticpreforms, wherein said temperature varying device has at least onetemperature varying unit arranged on a carrier which is rotatable abouta predefined axis of rotation, and said temperature varying unit has atleast two contacting devices which are suitable and intended forcontacting an outer wall of the plastic preforms and between which atleast one section of the plastic preforms can be received, and having adrive device for moving the at least two contacting devices in apredefined movement direction, wherein the apparatus has a detectiondevice for detecting at least intermittently a position of at least oneof the at least two contacting devices in the predefined movementdirection.
 2. The apparatus according to claim 1, wherein a plurality oftemperature varying units are arranged on the carrier and eachtemperature varying unit has a detection device for detecting at leastintermittently a position of the at least one contacting device in thepredefined movement direction.
 3. The apparatus according to claim 2,wherein the apparatus has a control device for controlling and orregulating the drive device as a function of the detected position ofthe at least one contacting device.
 4. The apparatus according to claim1, wherein the drive device is a pneumatic drive device.
 5. Theapparatus according to claim 1, wherein the detection device has aproximity sensing device.
 6. The apparatus according to claim 1, whereinthe apparatus has a time measuring device.
 7. The apparatus according toclaim 6, wherein the time measuring device is suitable and intended fordetecting a time interval between a first signal, which ischaracteristic of the actuation of the drive device, and a secondsignal, which is characteristic of a position of the contacting device.8. A method for treating containers, wherein a plurality ofsubstantially identical treatment stations are provided which treat thecontainers in a substantially identical manner by at least one treatmentelement, and wherein in each case the at least one treatment element ismoved relative to the container to be treated by pneumatic drives whichare assigned to the individual treatment stations, wherein at least onevalue which is characteristic of a geometric position of the at leastone treatment element relative to the container is detected by adetection device, and/or wherein a first time value is also determinedwhich is characteristic of a reaching of said geometric position of thetreatment element and the pneumatic drive is controlled and/or regulatedon the basis of said time value.
 9. The method according to claim 8,wherein said time values are measured for multiple treatment stationsand the pneumatic drives of the individual treatment stations arecontrolled in such a way that treatment times of the containers by thetreatment elements for the individual treatment stations are equalizedwith one another.
 10. The method according to claim 8, wherein aswitching point of at least one valve of the pneumatic drive device iscontrolled and/or regulated.
 11. The method according to claim 8,wherein the treatment element is a contacting device which makes contactwith a plastic preform in order to vary the temperature thereof.